Filter apparatus



April 30, 1963 G. HIRS FILTER APPARATUS 4 Sheets-Sheet 1 Original FiledJan. 15, 1959 EJQFIQEQCI I! mwu u minmvi I" IN VEN TOR. 55x5 Hues.

ATTORNEY:

4 Sheets-Sheet 2 [III/IIIIIIIIIIIIlIIIIIIIIlIlll/I/IZ INVENTOR. GENEMR5. W /W ATTORNEY.

April 30, 1963 G. HlRS FILTER APPARATUS Original Filed Jan. 15, 1959 MWk April 30, 1963 G. HIRS 3,087,620

FILTER APPARATUS Original Filed Jan. 15, 1959 4 SheetsSheet 3 IN VENTOR.

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G. HlRS 3,087,620

FILTER APPARATUS 4 Sheets-Sheet 4 m u inllll April 30, 1963 OriginalFiled Jan. 15, 1959 a *3 m R M. 250 FE M m w 3% \v N? M 7 M M finw? w 1& MW NV\ Q%\ M Kw HI'IWIYNE-K United States Patent 3,087,620 FILTERAPPARATUS Gene Hirs, 17208 Greenview Road, Detroit, Mich. Continuationof application Ser. No. 786,994, Jan. 15, 1959. This application Mar.27, 1961, Ser. No. 99,012 3 Claims. (Cl. 210-411) This invention relatesgenerally to filter apparatus and particularly to liquid filterapparatus.

This invention is a continuation of my copending application filedJanuary 15, 1959, Serial No. 786,994 for Filter Apparatus, nowabandoned.

It is an object of my invention to provide an improved liquid filterapparatus that makes it possible to achieve the benefits that resultfrom the filtering of liquid by means of a filter media submerged in theliquid.

Another object of the invention is to provide an improved liquid filterapparatus of a structural character such that it is possible to have asubmerged filter media that can be replaced without interruption of thefiltering operation.

Another object is to provide an improved submerged filter media type offilter apparatus constructed to provide for replacement of the filtermedia during filtering operation without the liquid lay-passing themedia.

Another object of the invention is to provide an improved liquid filterapparatus capable of achieving the benefits of suction induced flow ofliquid through the filter media without the suction induced differentialpressure on opposite sides of the filter media preventing replacement ofthe media.

Another object of the invention is to provide an improved filterapparatus of such construction and cooperation of its elements as toeffect efiicient filtering of liquid without the usual rapid clogging ofthe filter media.

Another object of the invention is to provide a filter apparatus of theabove mentioned character in which the filter media is automaticallyreplaced in response to a predetermined decrease in pressure on theoutlet side of the media caused by accumulation of foreign matter overthe inlet side.

A further object of the invention is to provide an ellicient yetinexpensive liquid filter apparatus.

Other objects of the invention will become apparent from the followingdetailed description, taken in connection with the accompanying drawingsin which:

FIG. 1 is a side view of my improved filter apparatus and a cutting toolmachine receiving a cutting oil and coolant from the filter;

FIG. 2 is a vertical sectional view of the filter apparatus shown partlyin elevation;

FIG. 3 is a fragmentary plan view of the filter apparat-us;

FIG. 4 is an enlarged cross sectional view, taken along line 44 of FIG.2;

FIG. 5 is another enlarged cross sectional view, taken aiong line 5--5of FIG. 2;

FIG. 6 is a fragmentary vertical sectional view, taken along line 6-6 ofFIG. 3;

FIG. 7 is another fragmentary vertical sectional view, taken along line77 of FIG. 3;

FIG. '8 is a fragmentary plan view, partly in section and taken in thedirection of the arrows 88 of FIG. 4;

FIG. 9 is a fragmentary side view of drive mechanism of the filterapparatus;

FIG. 10 is a fragmentary plan view, partly in section and taken alongline 10-10 of FIG. 5;

FIG. 11 is a detail sectional View, taken along line 11-11 of FIG. 9,and

FIG. 12 is another detail sectional view, taken along line 12-42 of FIG.9.

Patented Apr. 30, 1963 Referring to the drawings by characters ofreference, there is shown by way of illustrating the invention, acutting tool machine 20 to which my filter 22 is communicativelyconnected to supply a coolant or cutting oil to the tool. The coolant isdelivered from the filter 22 to the machine tool through a supply pipe.24 by a pump 26 and the coolant, containing dirt, chips and otherforeign matter, drains to a pan 28 whence the coolant drains back, byway of a return pipe 30, to the filter 22. A suitable electric motor 31may be used to drive the pump 26.

The filter 22 includes a tank 32 having a bottom wall 3 4, upright sideWalls 36, and opposite end walls 38 and 40'. An inlet 42 is provided inone of the tank side walls 36 to which the return pipe 30 is connected,such as, by suitable pipe fittings. At the bottom of the tank '32, Iprovide an outlet chamber 44' formed by upright side walls 46, end walls48 and a portion 50 of the tank bottom wall 34. These walls form abox-like structure that extends partly upwardly into the coolant, theupper edges of the walls defining an upwardly facing outlet 51 for thetank 32 for flow of the liquid coolant from the tank downwardly into theoutlet chamber 44. The upper edges of the outlet chamber walls 46 and 48also provides an upwardly facing seat 52.

In the outlet chamber 44 at the tank outlet 51 is a grate 54 that spansthe outlet and may be supported by angle members 56 on the walls 46 and48, and overlying and supported by the grate 54 is a liquid perviousbacking member or metal screen 58. Preferably the upper surface of thescreen 58 is in the same plane as the seat 52. The screen 56, grate 54'and angle supports 56 may be welded together and the supports may beWelded to the walls 46 and 48 of the outlet chamber 44. An outlet 57 forchain: ber 44 is provided and is connected by a pipe 59- to the intakeof pump 26.

A conveyor 60 is provided to hold a strip of filter media 62 down inoverlying relation to outlet 51 and against seat 52 to overcome thetendency of the media to float upwardly in the liquid and also to movethe media along a path of travel whereby to remove the foreign matterand replace the media over the outlet 51. To accomplish this, theconveyor 60 comprises two laterally spaced apart chains 64 andlongitudinally spaced hold down members or flight bars 66 that extendtransversely of and are carried by the chains. The flights 66 may bewelded or otherwise secured at their opposite ends to correspondinglinks respectively of the chains 64. As will be more fully un derstoodas the description proceeds, the flights 66 function to hold the filtermedia 62 down against the seat 52 and also function to grip and carrythe media along the path of travel when the media is moved to replacethe soiled portion and discharge the foreign matter from the tank.

A pair of drive sprockets 68, and three pair of guide sprockets 70, 72and 7-4 are arranged such that the conveyor 6th is guided thereby downinto the liquid adjacent tank end wall 38 and then horizontally acrossthe seat '52 in close proximity thereto and then upwardly out of theliquid near the tank end wall 40. The pair of drive sprockets 68 arefixed onto a drive shaft 76 which may be rotatably supported in bushings78 which may be suitably supported and secured to the tank side walls 36above the tank end wall 40. The pairs of guide sprockets 70, 72, and 74are rotatably mounted respectively on shafts 80, 82 and 84 which may bemounted on and suitably fixed to the tank side walls 36.

The chains 64 are of the endless type, and as seen from the side view ofFIG. 2, the centers of the sprockets define the apices of aquadrilateral. The arrangement of the sprockets is such that theconveyor 66 travel-s irom guide sprocket '70 downwardly at an angletoward tank end wall 33 and the conveyor traveling from guide sprockets74 to drive sprockets 68 travels upwardly and outwardly providing a rampup which the foreign matter is carried and discharged over the upperedge of tank end Wall 40. The upper sprockets 68 and 70 are above thelevel of the liquid in tank 32, the drive sprockets 68 preferably beingslightly above the guide sprocket 70. From the above description it willbe appreciated that I have provided an inverted conveyor having its leadside largely submerged in the liquid to guide the ftoatable filter media62 downwardly into the liquid over the liquid outlet 51 and then out ofthe tank.

To support the horizontal portion of the conveyor 60 in properrelationship to the outlet 51, the side walls 46 of the outlet chamber44 are provided with a closure and slideways including horizontal wallportions 85 that extend between walls 46 and tank side walls 36. Also,the closure and slideways include a horizontal portion 86 that extendsfrom end chamber wall 48 to end tank wall 38, and a horizontal portion87 that extends from the other chamber end wall 48 toward tank end wall46. These horizontal wall portions 85, 86 and 87 provide an uppersurface in the plane of and surrounding seat 52 for slidably supportingthe conveyor 60 over outlet 51.

One end of the drive shaft 76 projects beyond its adjacent bushing 78sufliciently to receive a driven sprocket 92 that is driven by a chaindrive 94 from the shaft of a speed reduction mechanism 96 which is inturn driven by a suitable electric motor 98.

A second endless conveyor 1% is provided to cooperate with and aidconveyor 60 in moving the filter media 62 along its path of travel toreplace the soiled media over outlet '51. The conveyor .100 is arrangedat the same angle as the ramp portion of conveyor 62, the conveyorhaving their lead sides in back-to-back relationship so as to grip thefilter media there-between, as illustrated in FIG. 2. The conveyor 100may be of any suitable type, such as the metallic belt, the constructionof which is best shown in FIG. 10. This is a well known link typeconstruction comprising a plurality of sinuously formed sheet metalcross members or flights 162 that are pivotally inter-connected byparallel cross rods 104. In addition to the strength and flexibility ofthe conveyor 1%, the upper edges of the sinuous flights 102 collectivelypresent a large gripping surface to urge the filter media along its pathof travel on shifting of the filter media in the replacement operation.

The conveyor 100 travels about an upper pair of driven sprockets 106 anda lower pair of guide sprockets 108 arranged such that the upper or leadside of conveyor 1% is parallel to the lower lead side of conveyor 60.The upper sprockets 106 of conveyor 100 are fixed on a driven shaft :108that may be suitably journaled on mountings on the tank sisde walls 36,and the guide sprockets 108 are mounted for rotation on a shaft 110which may be suitably fixed in and to side walls 36. Spaced supports 112provide a ramp and slideway under the lead side of conveyor 100, theramp being supported by cross members 114 which may be welded orotherwise secured to the tank side walls 36. The trailing side ofconveyor 106 is preferably supported and slidably guided on tank endwall 40 which, .as shown in FIG. 2, is inclined parallel to the ramp112. The conveyors 60 and '100 are driven at the same rate of speed bymotor 98 which drives conveyor 100 through gears 116 and 118 which arerespectively keyed to shafts 76 and 108.

The electric motor 31 that drives the pump 26 may be connected by leads121 and 122 to a suitable source of electric power, and in lead 121there may be provided the usual line switch 124. Controlling theconveyor drive motor 98 is a pressure responsive switch 126 which isrepresented as being operable by a closed bellows 128 that is connectedby a pipe 130 to the intake pipe 59 of pump 26. Thus, the switch 126 isresponsive to a predetermined decrease in pressure in outlet chamber 44,indicative of a need for replacement of the filter media portion overoutlet 52.

Operation In operation of my filter apparatus the pump 26 is startedwhen line switch 124 is closed, and the pump operates continuously, orso long as it is desired to supply coolant to the cutting tool ofmachine 20. As previously mentioned, the coolant is circulated betweenthe machine drain pan 28 and the filter apparatus tank 32 and thequantity of coolant employed in the circulatory system determines theliquid level in the tank. As the pump 26 operates, it draws the liquidin tank 32 through the filter media overlying outlet 51 into the outletchamber 44 whence the clean liquid flows to the intake of pump 26through pipe 59 and is delivered through pipe 24 to the cutting tool ofmachine 20. Some of the larger particles of dirt and other foreignmatter in the contaminated coolant are suspended in the liquid in tank32 and under the current inducing influence of the liquid entering thetank at inlet 42 move toward and settle on that portion of the filtermedia extending up the ramp 12 of the conveyor 60. In this manner someof the foreign matter can be removed from the liquid without the need offiltering out the matter at the outlet 51 with the advantage that suchmatter does not contribute to decrease in flow rate through the media atoutlet 51. Other foreign matter will settle on the filter media at theoutlet 51 under the influence of pump 26, but in contrast to thesituation prevailing in high pressure systems, the foreign matter is notpacked into the interstices of the media and thus does not rapidly clogthe media. Instead the foreign matter piles up on the media forming agood filter aid therefore, the rate of flow being substantiallyinversely proportional to the increase in the depth of the foreignmatter on the media. This means that a less frequent replacement of themedia over the outlet is required whereby optimum liquid filteringefliciency is attained. However, eventually the liquid flow rate willdecrease to an inemcient rate as will be indicated by a predetermineddecrease in pressure in outlet chamber 44 for which predeterminedpressure switch 126 is set. When this predetermined pressure is reached,switch 126 closes and starts motor 98 which simultaneously drives bothconveyors 60 and to move the filter media 62 along its path of travel,indicated by the arrows so as to replace at least part of the media overoutlet 51 and at the same time feed the soiled media and foreign matterthereon out of the liquid at the top of the ramp and discharge the mediaand foreign matter over the end wall 40 where a disposal container (notshown) may be provided. When the conveyors 60 and 1% are first startedto move, the pressure differential of the liquid in tank 32 and outletchamber 40 holding the media 62 against screen 58 is sufficient toprevent movement of the media with the conveyors. As a result, theconveyors move relative to the media for a short distance during whichmy hold-down flights 66 function to scrape away some of the foreignmatter from the media which increases flow from tank 32 to outletchamber 44 with accompanying decrease in the pressure differential to apoint Where the full force of the conveyors prevail in moving the media.When the conveyor flights scrape away some of the foreign matter fromthe filter media, the liquid rate of flow increases through the scrapedaway areas, but this will not appreciably increase the pressure inchamber 44 to the point where switch 126 would open, provided that thecapacity of the pump 26 is made such that it exceeds the increasedliquid fiow into the chamber. As an alternative way of maintaining themotor 98 operating for a desired interval, the pressure switch 126 maybe of the slow closing type, or a timer, such as the timer 154 of FIG.13 may be employed to control the motor 98. When the pressuredifferential between tank 32 and outlet chamber 44 decreases to apredetermined pressure, switch 126 opens and stops motor 98.

Referring now to FIGS. 13 to 15 inclusive, these views show amodification of my filter apparatus involving another way in which todecrease the pressure differential on the soiled filter media 62 so thatthe media may be moved along its path of travel by the conveyors withoutstopping the suction pump 26. As the apparatus of FIGS. 13, 14 and 15 issimilar in many respects to the apparatus of FIGS. 1 to 12, like partsare designated by like characters of reference to avoid unnecessaryrepetitious description. In the modification, an auxiliary or by-passchamber 132 is separated from main chamber 44 by a partition 134 and hasan upwardly facing outlet and seat 136 for the filter media 62. Theby-pass chamber 1352 has an outlet 138 connected by a pipe 140 to thepipe 59 by means of a three-way valve 142 which includes a rotatablevalve member 144. Normally, the valve member 144 is positioned toestablish communication between main chamber 44 and pipe 59 and blockcommunication between pipes 140 and 59, the valve member being rotatableninety degrees to the position shown in FIG. 15 to establish opencommunication between pipes 140 and 59 and block communication betweenmain chamber 44 and pipe 59. An air cylinder 146 may be employed toactuate valve member 144 and may be controlled by a solenoid 148.Solenoid 148 is in series circuit with the normally closed contacts 152of an electrical timer 154 and the normally open contacts 126 of thepressure responsive switch 123. Relay 150 has a pair of contacts 156 inseries circuit with the motor 98, and another pair of contacts 158 inseries circuit with the timer 154. Also the relay contacts 158 are inseries with the normally closed timer contacts 152 and the relay 150which provides a holding circuit holding relay 150 energized after thepressure switch 128 initiates energization of relay 150 and soonthereafter opens its contacts 126 in response to the higher pressure inchamber 132.

When line switch 124 is closed, the motor 3 1 drives pump 26 which thenfunctions to reduce the pressure in chamber 44 causing How of liquiddown through that portion of the filter media 62 overlying the outlet51. The filtered liquid flows from chamber 44 through pipe 59 to thepump 26 which delivers the clean liquid to the tool of machine 20 fromthe pan 28 of which contaminated liquid drains back to tank 32 throughreturn pipe 30. In time, the accumulation of foreign matter collected onthe filter media 62 over outlet 51 reduces filtering efficiency to thepoint where replacement of the media is desirable and pressure switch128 is set to close in response to a predetermined decrease in pressurein chamber 44 to effect the automatic replacement of the media. When theswitch 150 closes, the solenoid 148 is energized through the circuitincluding the normally closed contacts 152 of the timer 154, andair-cylinder 146 then actuates valve member 144 to connect thecontinuously operating pump 26 to the auxiliary chamber 132. Thispermits continued flow of liquid to pump 26, but from auxiliary outletchamber 132 where the filter media is relatively clean or has littleforeign matter collected thereon compared to the media over chamber 44.Thus, the pressure differential on opposite sides of the media overlyingchamber 44 is decreased to allow movement of the filter media with theconveyors when the motor 121) is started. Simultaneously withenergization of the valve controlling solenoid 148 through the seriescircuit including the normally closed contacts 152 and the now closedcontacts 126, the relay 150 is energized, closing both sets of switches156 and 158. The closing of switch contacts 156 starts motor 93 whichthen moves the conveyors 6G and 106) to move the filter media 62 alongits path of travel out of the tank 32. Closing of the other contacts 153establishes a holding circuit for the relay through the normally closedtimer contacts 152, and also through the timer 154. The timer 154 is setto open its contacts 152 at an interval corresponding to the timerequired for the replacement of a desired length of the filter media atthe outlet chamber 44. The timer 154 is provided so that the motor 98will not be stopped as soon as the valve 144 operates to establishcommunication of the pump 26 and auxiliary chamber 132 as otherwisewould occur since the pressure in the auxiliary chamber 132 would behigher than the pressure setting of switch 128.

From the foregoing description, it will now be appreciated that I haveprovided an improved filter apparatus, the components of which cooperateto make it possible to replace a used filter media without need ofinterrupting the filtering operation. Also, it will be appreciated thatin my filter apparatus, the filter media is submerged in the liquid tobe filtered and is guided over an outlet on which a reduced pressure isapplied to draw the liquid through the media so as to decrease thetendency to clog the filter media. Furthermore, I have provided a filterapparatus having an inverted conveyor which functions to hold the filtermedia down over the outlet and move the media during filtering operationto replace the soiled portion or part thereof and also carry the soiledmedia and dirt out of the apparatus. In addition, I have arranged for asubmerged ramp portion of the conveyor to pick up suspended foreignparticles whereby to reduce the amount of foreign matter that willsettle on the media at the outlet with a corresponding increase in theintervals of replacing of the media.

While I have shown and described the invention in considerable detail,it will be understood that various changes may be made Without departingfrom the spirit and scope of the invention.

What I claim is:

1. In a filter apparatus for removing contaminant particles from acontaminated liquid, a tank structure subdivided by common stationaryWall means into an upper compartment adapted to maintain a substantiallyconstant body of contaminated liquid and a lower compartment adapted tobe filled with filtrate, said wall having openings thereininterconnecting said compartments, a perforate filter medium in the formof a fibrous web, means for supplying said web from a roll, the webbeing supported by said wall means and having a portion interposedbetween said compartments to remove said particles from liquid flowingthrough said openings therebetween, such particles accreting on theupper surface of said web, an endless conveyor in the form of a closedloop having a lower reach depending into said upper compartment toconfine the web against said wall means for support thereby and saidconveyor having transverse flights contacting the upper surface of saidinterposed portion of said web and any contaminant accreted thereon,actuatable power means for advancing said conveyor in said loop withsaid flights advancing the interposed portion of said web and draggingout said accreted contaminant, a filtrate pump having its intakeconnected to said lower compartment to create a vacuum thereinsupplementing the static head of said contaminated liquid in said uppercompartment, and means for reducing said vacuum prior to actuation ofsaid power means.

2. In a filter, an open-topped tank adapted to maintain a body ofcontaminated liquid at atmospheric pressures and having wall meansbeneath the level of said body of liquid provided with an outletopening, means defining a vacuum chamber underlying said wall means andhaving an upper opening registering with said outlet opening, saidvacuum chamber being sealed continuously from the atmosphere by liquidin the tank, a perforate filter medium of a size and extent to at leastcover said openings and effective to remove contaminant from liquidflowing from said tank into said chamber, means for withdrawing filtrateliquid from said chamber to create a sub-atmospheric pressure in saidchamber, thereby inducing liquid flow through the medium at an effectivepressure difiFerential greater than that resulting from the depth ofliquid overlying the medium, an endless conveyor in the form of a loophaving a lower reach depending into said tank and having transverseflights overlying said medium in contact with any contaminant thereon,power means actuatable for advancing said conveyor in its loop to removecontaminant from the tank, means responsive to a decrease in thepressure in said vacuum chamber for actuating said power means.

3. In a filter apparatus for removing contaminant particles from acontaminated liquid, a tank structure subdivided by stationary wallmeans into an upper compartment for maintaining a substantially constantbody of contaminated liquid and a lower compartment for receivingfiltrate, said lower compartment being sealed from the atmosphere, saidwall having openings therein interconnecting said compartments, aperforate filter medium supported by said wall means and interposedbetween said compartments to remove said particles from liquid flowingthru said openings therebetween, such particles accreting on the uppersurface of said medium, an endless conveyor in the form of a closed loophaving a lower reach depending into said upper compartment to besupported by said Wall means and having transverse flights contactingthe upper surface of said medium and any contaminant accreted thereon,power means for advancing said conveyor in said loop with said flightsdragging out said accreted contaminant, means including a timer forintermittently actuating said power means so that contaminant accretedon said medium between successive advancements of said conveyor servesas a filter aid, said timer insuring continued advancement of saidconveyor for a predetermined period of time, and a fiitrate pump havingits intake connected to said lower compartment to create a vacuumtherein supplementing the static head of said contaminated liquid insaid upper compartment to induce the flow of liquid through said medium.

References Cited in the file of this patent UNITED STATES PATENTS392,606 Heywood Nov. 13, 1888 1,403,369 Anderson Jan. 10, 1922 2,665,812Crane Jan. 12, 1954 2,675,129 Doubleday Apr, 13, 1954 2,861,688 HarmsNov. 25, 1958 2,867,324 Hirs Jan. 6, 1959

2. IN A FILTER, AN OPEN-TOPPED TANK ADAPTED TO MAINTAIN A BODY OFCONTAMINATED LIQUID AT ATMOSPHERIC PRESSURES AND HAVING WALL MEANSBENEATH THE LEVEL OF SAID BODY OF LIQUID PROVIDED WITH AN OUTLETOPENING, MEANS DEFINING A VACUUM CHAMBER UNDERLYING SAID WALL MEANS ANDHAVING AN UPPER OPENING REGISTERING WITH SAID OUTLET OPENING, SAIDVACUUM CHAMBER BEING SEALED CONTINUOUSLY FROM THE ATMOSPHERE BY LIQUIDIN THE TANK, A PERFORATE FILTER MEDIUM OF A SIZE AND EXTENT TO AT LEASTCOVER SAID OPENINGS AND EFFECTIVE TO REMOVE CONTAMINANT FROM LIQUIDFLOWING FROM SAID TANK INTO SAID CHAMBER, MEANS FOR WITHDRAWING FILTRATELIQUID FROM SAID CHAMBER TO CREATE A SUB-ATMOSPHERIC PRESSURE IN SAIDCHAMBER, THEREBY INDUCING LIQUID FLOW THROUGH THE MEDIUM AT AN EFFECTIVEPRESSURE DIFFERENTIAL GREATER THAN THAT RESULTING FROM THE DEPTH OFLIQUID OVERLYING THE MEDIUM, AN ENDLESS CONVEYOR IN THE FORM OF A LOOPHAVING A LOWER REACH